Process of producing acetyl-cellulose-coated material.



LEONHARD LEDERER, F SULZBACH-OBERFALZ,GERMANY.

PROCESS OF PRODUCING ACETYL-CELLULOSE-GOATED MATERIAL.

No Drawing. Original application filed May 29, 1902,

filed March 29, 1905.

' Acetyl-Cellulose-Coated Material, of which the following is a specification:

This invention relates to the production of material, such as yarns, fabrics, paper and the like, also nunuifactured cellulose, having a surface-coating of acetyl-eellulose, this being a divisional application of my application Serial No. 109,566, filed May 2%), 1902.-

The invention consists in the process hereinafter described, which comprises the steps of subjecting a body containing cellulose to the action of an acetylizing reaction-mixtur'e until a film of acetyl-cellulose is formed .upon the surface of the material, then discontinuing the action of the reaction mixture, and astly removing the acid by washing with water;

The invention consists further in the new product thus produced, said product consisting at its interior of cellulose or a body containing cellulose and having, a surfacefilm of acetyl-cellulose.

It is desirable for many urposes to partially aeetylize cellulose an bodies containing cellulose, such as yarn, fabrics, paper or the like, so that the particular object treated shall beprovided with a surface-layer con-- taiuing acetyl-c'ellulosc, while still containing at its interior unaltered cellulose. For obtaining this result, the cellulose or bodies containing cellulose are immersed in an acetylizing reaction-mixture and allowed to remain therein for a short time, so that an acetylization through the entire mass of cellulose cannot take place. The bodies so treated are thereby provided only with a thicker or thinner surface-film of acetylcellulose, according to the length of time during which they are subjected to the action Specification of Letters Eatent.

Patented Apr. 5, 1910. Serial No. 109,566. Divided and this application Serial No. 252,673.

of the reaction-mixture. The bodies are then washed with water. For instance, a fabric containing cellulose is immersed in acetic anhydrid to which about .5% sulfuric acid has been added, and allowed to remain in said solution for about ten ninutes. The fabric thus provided with a more or less thick surface-coating of acetyl-cellulose is then removed from the solutlon and freed from the absorbed acid by Washing with Water.

As examples of the application of the process may be mentioned the production of waterproof yarns and textile fabrics, imparting a gloss to fabrics, and the reparation and improvement of yarns ane fabrics before dyeing them. I

Having thus described my invention, I claim as new and desire to secure by Letters Patent 1. The herein described process of producing acetyl-cellulose coated material, which consists in subjecting a body containing cellulose to the action of an acet lizingreaction-mixture until a film of acety -cellulose of the desired thlckness 1s formed there- 'on, then discontinuing theaction Lof said reaction mixture, and lastly removing the acid by washing with water.

2. The herein described process of prowhich consists in subjecting a body containing cellulose to the action of a solution of acetic unhydrid and sulfuric acid until a filln of acct l-cellulose of the desired thickness is forme thereon, then discontinuing the action of said solution, and then removing the acid by washing with water.

In testimony, that I claim the foregoing asmy invention, I vhave signed myname in presence of two subscribin witnesses.

LEONHART) LEDERER. Witnesses:

WALTHER D6111, OSCAR BOOK.

ducing acetyl-cellulose coated material, 

